Summer Watering

June 5th, 2026

Deep Roots Begin with Deep Watering

One of the most important lessons dahlia growers learn is that healthy plants begin beneath the soil.

When dahlias struggle to thrive, wilt during warm afternoons, or produce fewer blooms than expected, watering is often at the heart of the issue. While watering may seem simple, understanding when and how to water dahlias can make a tremendous difference in the health and performance of your plants throughout the growing season.

The Early Days: Less Water Than You Might Think

Many new gardeners are surprised to learn that newly planted dahlia tubers require very little water.

At planting time, the tuber already contains the energy and moisture it needs to begin waking up beneath the soil. During these first weeks, the tuber is quietly responding to warming soil temperatures and preparing to send roots and sprouts toward the surface.

In most climates, excessive watering during this stage can do more harm than good. Soil that remains overly wet before sprouts emerge can increase the risk of tuber rot and delay healthy growth.

Here in Idaho's Treasure Valley, spring moisture and occasional rainfall are often enough to support newly planted tubers until growth begins. This year, we haven't had any rain for weeks. We have benefited from a weekly watering schedule because our soil is so dry. In hot or arid climates, a light watering once each week may be beneficial.

Paying attention to the moisture content of your soil and patience during this stage is often one of the best gifts you can give your dahlias.

Everything Changes Once Sprouts Appear

The moment your dahlias emerge from the soil, their needs begin to change.

What started as a dormant tuber quickly becomes an actively growing plant. New roots begin stretching deeper into the soil while stems and foliage work hard to capture sunlight and fuel future blooms.

As growth accelerates, dahlias become surprisingly thirsty plants.

The goal now is no longer simply keeping the soil moist. The goal is encouraging roots to grow deep and strong.

Why Deep Watering Matters

Many gardeners make the mistake of watering lightly and frequently. This works well in the beginning but once growth begins so does deep watering.

While this may temporarily dampen the soil surface, it rarely provides enough moisture for roots growing deeper underground. As a result, plants develop shallow root systems that become vulnerable during hot weather.

Deep watering encourages roots to follow moisture farther into the soil profile. Plants with deeper root systems are typically stronger, more resilient during summer heat, and better equipped to support large numbers of blooms.

Strong stems, healthy foliage, and abundant flowers all begin with healthy roots.

How Much Water Do Established Dahlias Need?

Once dahlias are actively growing, most gardens benefit from deep watering three to four times each week.

The objective is to soak the soil thoroughly, allowing moisture to penetrate approximately 8 to 10 inches below the surface where roots can access it.

At Flaming Acres, our field-grown dahlias are watered deeply using overhead irrigation. During warm summer weather, sprinklers often run for 45 to 60 minutes at a time to ensure moisture reaches the root zone. During periods of extreme heat, longer watering sessions may be necessary.

Every garden is different, but the principle remains the same: water deeply enough that the roots have a reason to grow deeper.

Looking Beyond the Surface

It's easy to assume watering is about keeping the top of the soil wet.

In reality, successful watering is about what happens beneath the surface.

Every deep watering session is encouraging stronger roots, sturdier stems, healthier plants, and ultimately more blooms. The flowers we enjoy later in the season are often the result of decisions we make long before the first bud appears.

From the Fields of Flaming Acres

As our nearly 6,000 dahlia plants continue growing this season, we are constantly reminded that beautiful blooms begin underground. While flowers may capture our attention, the true work of the plant is happening where we cannot see it.

By watering deeply and consistently, we give our dahlias the foundation they need to thrive through the long days of summer.

Because deep roots today become beautiful blooms tomorrow.

Happy Growing,

Debra Flaming

Flaming Acres Dahlias